CN111107275B - Low-energy-consumption navigation device - Google Patents

Low-energy-consumption navigation device Download PDF

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CN111107275B
CN111107275B CN201910335075.8A CN201910335075A CN111107275B CN 111107275 B CN111107275 B CN 111107275B CN 201910335075 A CN201910335075 A CN 201910335075A CN 111107275 B CN111107275 B CN 111107275B
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image
digital
processor
navigation device
quality
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CN111107275A (en
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李永作
林凯文练力
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Pixart Imaging Inc
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Pixart Imaging Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/70—Circuitry for compensating brightness variation in the scene
    • H04N23/73—Circuitry for compensating brightness variation in the scene by influencing the exposure time
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
    • G06F1/26—Power supply means, e.g. regulation thereof
    • G06F1/32—Means for saving power
    • G06F1/3203—Power management, i.e. event-based initiation of a power-saving mode
    • G06F1/3234—Power saving characterised by the action undertaken
    • G06F1/325—Power saving in peripheral device
    • G06F1/3259—Power saving in cursor control device, e.g. mouse, joystick, trackball
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
    • G06F3/0354—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
    • G06F3/038—Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/65—Control of camera operation in relation to power supply
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/95—Computational photography systems, e.g. light-field imaging systems
    • H04N23/951—Computational photography systems, e.g. light-field imaging systems by using two or more images to influence resolution, frame rate or aspect ratio
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/50—Control of the SSIS exposure
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/60—Noise processing, e.g. detecting, correcting, reducing or removing noise
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/70—SSIS architectures; Circuits associated therewith
    • H04N25/71—Charge-coupled device [CCD] sensors; Charge-transfer registers specially adapted for CCD sensors
    • H04N25/75—Circuitry for providing, modifying or processing image signals from the pixel array
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/70—SSIS architectures; Circuits associated therewith
    • H04N25/76—Addressed sensors, e.g. MOS or CMOS sensors
    • H04N25/77—Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/0304—Detection arrangements using opto-electronic means
    • G06F3/0317—Detection arrangements using opto-electronic means in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/033—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
    • G06F3/0354—Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
    • G06F3/03543—Mice or pucks
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/30—Subject of image; Context of image processing
    • G06T2207/30168—Image quality inspection
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D10/00—Energy efficient computing, e.g. low power processors, power management or thermal management

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Human Computer Interaction (AREA)
  • Computing Systems (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Automation & Control Theory (AREA)
  • Studio Devices (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)

Abstract

A navigation device includes an image sensor, an analog-to-digital converter, and a processor. The image sensor outputs an analog image during exposure. An analog-to-digital converter converts the analog image to a digital image at a resolution. The processor judges the image quality of the digital image and adjusts at least one of the exposure period of the image sensor and the resolution of the analog-digital conversion according to the image quality, so that the calculation energy consumption is adjusted by changing the data length actually processed by the processor.

Description

Low-energy-consumption navigation device
Technical Field
The present invention relates to a navigation device, and more particularly, to a navigation device that reduces power consumption by reducing a bit length of each digital data actually processed by a processor.
Background
Although touch panels have become a new choice for human-machine interfaces, some situations still require interaction with the image display system through the navigation device.
Reducing the energy consumption of navigation devices has been one of the issues in the development of navigation devices for a long time. In particular, wireless navigation devices, where the power consumption of the components must be reduced as much as possible.
One well-known method is to control the navigation apparatus to enter a sleep mode or a standby mode to reduce power consumption when the navigation apparatus is not used for a predetermined period of time. However, merely saving power during non-operation is not sufficient to effectively extend battery life, and the navigation device is preferably capable of low power consumption also during operation.
Accordingly, the present invention provides a navigation device capable of reducing the bit length of each digital data processed by a processor during operation according to the image quality of a digital image to reduce the amount of computation of the processor, thereby reducing the overall power consumption.
Disclosure of Invention
The present invention provides a navigation device that changes the conversion resolution of an analog-to-digital converter (ADC) according to the image quality of a digital image to adjust the operational bit length of a processor, thereby reducing overall power consumption when operating with a relatively high quality work surface.
The invention also provides a navigation device which changes the exposure time of the image sensor according to the image quality of the digital image and adjusts the operation bit length of the processor, thereby reducing the overall energy consumption when the work surface with relatively high quality is operated.
The invention provides a navigation device including an image sensor, an analog-to-digital converter, and a processor. The image sensor includes an array of pixels for outputting an image frame. The analog-to-digital converter is used for converting each pixel data of the image frame into digital data with conversion resolution and generating a digital image. The processor is configured to calculate an image quality of the digital image and to change the conversion resolution of the analog-to-digital converter based on the image quality.
The invention also provides a navigation device comprising an image sensor, an analog-to-digital converter and a processor. The image sensor includes a pixel array for outputting an image frame at an exposure time. The analog-to-digital converter is configured to convert each pixel data of the image frame into digital data of a predetermined bit at a fixed conversion resolution and generate a digital image. The processor is configured to calculate an image quality of the digital image and to change the exposure time and a bit length of the predetermined bits of the digital data processed thereby according to the image quality.
The invention also provides a navigation device comprising an image sensor, an analog-to-digital converter and a processor. The image sensor includes a pixel array for outputting an image frame at an exposure time. The analog-to-digital converter is used for converting each pixel data of the image frame into digital data with conversion resolution and generating a digital image. The processor is used for calculating the image quality of the digital image and reducing the bit length of each digital data of the digital image processed by the processor according to the calculated image quality so as to reduce energy consumption.
In the navigation device according to the embodiment of the present invention, when the conversion resolution of the analog-to-digital converter is reduced, since the gain noise usually does not exceed the digital noise, the gain value of the analog amplifier may be increased to amplify the pixel data. In addition, when the gain value of the analog amplifier is increased, the exposure time of the image sensor and the lighting period of the light source can be simultaneously shortened, so that the overall energy consumption is further reduced.
In order that the manner in which the above recited and other objects, features and advantages of the present invention are obtained will become more apparent, a more particular description of the invention briefly described below will be rendered by reference to the appended drawings. In the description of the present invention, the same components are denoted by the same reference numerals, and the description thereof is made herein.
Drawings
Fig. 1 is a block diagram of a navigation device of a first embodiment of the present invention;
FIG. 2 is a schematic diagram of controlling exposure time according to one embodiment of the present invention;
FIG. 3 is a schematic diagram of a filter kernel of a navigation device suitable for use in embodiments of the present invention;
FIG. 4 is a schematic diagram of a navigation device according to a first embodiment of the present invention;
FIG. 5 is a timing diagram illustrating operations of the navigation device according to the first embodiment of the present invention;
FIG. 6 is a block diagram of a navigation device of a second embodiment of the present invention;
FIG. 7 is a diagram illustrating an operation of a navigation device according to a second embodiment of the present invention.
Description of the reference numerals
100. 600 navigation device
11. 61 light source
12. 62 image sensor
13. 63 analog amplifier
14. 64A/D converter
15. 65 processor
Detailed Description
Referring to fig. 1, a block diagram of a navigation device 100 according to a first embodiment of the invention is shown. The navigation device 100 is used to calculate the relative motion with the work surface S; wherein the relative motion can be a movement of at least one of the navigation device 100 and the work surface S. The navigation device 100 is, for example, an optical mouse or an optical finger navigation device, and is used for calculating a displacement amount or a track according to features in the acquired image.
The navigation device 100 includes an image sensor 12, an analog-to-digital converter (ADC)14, and a processor 15. In one non-limiting embodiment, the image sensor 12, the analog-to-digital converter 14, and the processor 15 are fabricated as a detection chip and enclosed in the same package, for example.
Image sensor 12 includes a pixel array (e.g., fig. 1 shows a pixel array including 9 pixels) for outputting image frame F at an exposure time; wherein, the exposure time is fixed or adjustable and is determined according to different applications.
Fig. 2 shows a schematic diagram of adjusting exposure time. The pixel array of the image sensor 12 includes a plurality of pixels, each of which includes, for example, a grating switch SWshut and at least one photodiode PD. The processor 15 may control the on-time or off-time of the raster switch SWshut by sending a control signal Se to change the exposure time of each pixel. Each pixel of the image sensor 12 may have a known 3-transistor (3T), 4-transistor (4T), or 5-transistor (5T) structure, without particular limitation.
An analog-to-digital converter 14 for converting each pixel data of the image frame F into digital data at a conversion resolution (conversion resolution), the digital data of all pixels forming a digital image; wherein the conversion resolution is fixed or adjustable, depending on the application. The conversion resolution determines the bit length (bit length) of each digital data; although the higher the conversion resolution, the higher the accuracy, the longer the bit length, the higher the amount of data processing operations performed by the processor 15.
The processor 15 is, for example, a Digital Signal Processor (DSP) for post-processing the digital data of the digital image output from the analog-to-digital converter 14, such as calculating the displacement amount or tracking the trajectory. In the present invention, the processor 15 is further configured to calculate an image quality of the digital image, and reduce a bit length of each digital data processed by the processor according to the image quality, so as to reduce energy consumption.
The processor 15 may calculate the image quality using a suitable method. In one non-limiting embodiment, the processor 15 first filters the digital image using a DC removal filter (DC removal filter), for example, a filter kernel (filter kernel) as shown in FIG. 3, to produce a filtered digital image. Processor 15 then counts the number of pixels in the filtered digital image whose filtered digital value exceeds a predetermined threshold as a way of determining image quality. The higher the number of pixels counted, the better the image quality is represented, meaning that the navigation device 100 is more suitable to operate on the current work surface S. Conversely, a lower number of pixels counted indicates a poorer image quality.
In other embodiments, the processor 15 may also count the number of pixel differences of adjacent pixels in the digital image that exceed the difference threshold, and use the counted number as a way to determine the image quality. The higher the number of counts, the better the image quality is indicated. Furthermore, the image quality may also be expressed according to other characteristics such as the number of edges (edges), contrast (contrast) of the digital image, and the like, without any particular limitation.
In the first embodiment of the present invention, the processor 15 is configured to calculate the image quality of the digital image output by the analog-to-digital converter 14, and to change the conversion resolution of the analog-to-digital converter 14 according to the image quality. For example, when the calculated image quality is greater than or equal to the quality threshold, the processor 15 generates a control signal Sr to the analog-to-digital converter 14 to lower the conversion resolution of the analog-to-digital converter 14. For example, the adc 14 samples with N1 bits (e.g., but not limited to 10 bits) before reducing the conversion resolution, and samples with N2 bits (e.g., but not limited to 6 bits) after reducing the conversion resolution; wherein N2< N1. By this means, the bit length of each piece of digital data post-processed by the processor 15 is reduced by reducing the conversion resolution of the analog-to-digital converter 14, so that the overall amount of computation can be reduced.
Conversely, when the image quality is less than the quality threshold, the processor 15 increases the conversion resolution so that each sample has more bits.
Referring to fig. 4, it is a schematic diagram of the navigation device 100 according to the first embodiment of the invention. The navigation device 100 may, for example, operate in two modes, a first resolution (e.g., 10 bits) and a second resolution (e.g., 6 bits); in fig. 4, the second resolution selection is less than the first resolution.
When the adc 14 generates digital images at a first resolution and the determined image quality SQCNT is greater than or equal to the first quality threshold TH1, indicating that the features of the current working surface S are significant, the processor 15 changes the first resolution of the adc 14 to a second resolution by sending a control signal Sr to the adc 14. Conversely, when the analog-to-digital converter 14 generates the digital image at the second resolution and the determined image quality SQCNT is less than the second quality threshold TH2, indicating that the features of the current working surface S are not significant enough, the processor 15 changes the second resolution of the analog-to-digital converter 14 to the first resolution by sending a control signal Sr to the analog-to-digital converter 14. In the present embodiment, the first quality threshold TH1 is preferably different from the second quality threshold TH 2.
Referring to fig. 5, a timing diagram of the operation of the navigation device 100 according to the first embodiment of the invention is shown. In addition to the above method, the present embodiment further reduces the overall energy consumption of the navigation device 100 as described below.
The navigation device 100 also includes an analog amplifier (e.g., PGA)13 that amplifies each pixel data of the image frame F by a gain value G to generate an amplified image frame Fa. The analog-to-digital converter 14 is used to convert the amplified image frame Fa into a digital image. In this embodiment, when the processor 15 controls the adc 14 to reduce the conversion resolution, since the gain noise (gain noise) is usually lower than the digitization noise (digitization noise), increasing the gain value G of the analog amplifier 13 does not significantly increase the noise in the digital image generated by the adc 14. For example, the processor 15 controls the analog amplifier 13 to adjust the gain value G by sending a control signal Sg to the analog amplifier 13.
After the gain value G of the analog amplifier 13 is increased, the processor 15 synchronously shortens the exposure time of the image sensor 12 in order to maintain the maximum gray-scale value of the digital image constant. As shown in FIG. 5, when the analog amplifier 13 is operated at a lower gain value G1 (relatively higher conversion resolution N1), the image sensor 12 is exposed for a time t1Acquiring an image frame F; while when the analog amplifier 13 is operated at a higher gain value G2 (relatively lower conversion resolution N2), the image sensor 12 is changed to the exposure time t2Acquiring an image frame F; wherein t is2<t1。
In some embodiments, the navigation device 100 may also include a light source 11, such as a coherent, non-coherent or partially coherent light emitting diode or laser diode emitting a predetermined spectrum, such as infrared light. The light source 11 is used to provide the light required by the image sensor 12 to acquire the image frame F, for example to illuminate the work surface S. The lighting time of the light source 11 at a time may be adjusted with respect to the exposure time of the image sensor 12 as long as it is equal to or greater than the exposure time. In one non-limiting embodiment, the processor 15 controls the image sensor 12 to reduce the exposure time (e.g., from t as shown in FIG. 5) when the control signal Se is applied to the image sensor1Shortened to t2) In this case, the processor 15 also controls the light source 11 to shorten the lighting time (for example, from T shown in fig. 5)1Shortened to T2) (ii) a Wherein T1 is not less than T1And T2T is greater than or equal to2. Preferably, the brightness of the light source 11 is kept constant every time it is turned on.
Referring to fig. 6, a block diagram of a navigation device 600 according to a second embodiment of the present invention is also shown, which includes a light source 61 for providing detection light, an image sensor 62 having a pixel array for outputting an image frame F based on an exposure time, and an analog amplifier 63 for amplifying each pixel data of the image frame F to output an amplified image frame Fa.
The second embodiment is different from the first embodiment in that the analog-to-digital converter 64 in the second embodiment is configured to convert each pixel data of the image frame F (or the enlarged image frame Fa) into digital data of a predetermined bit (for example, N bits) at a fixed conversion resolution and generate a digital image. The processor 65 is configured to calculate an image quality of the digital image and to change an exposure time of the image sensor 62 and a bit length of the predetermined bits of the digital data to be processed according to the calculated image quality. In other words, the processor 65, while reducing the bit length in the predetermined bits of each digital data of the digital image it processes, also reduces the exposure time of the image sensor 62 so that the maximum gray-scale value of the digital data of each pixel of the digital image does not exceed the maximum range of digital data processed by the processor 65. In other words, although the conversion resolution of the analog-to-digital converter 64 is fixed, the higher bit (higher bit) of the predetermined bits of the digital data is controlled not to contain the characteristic information of the work surface S because the exposure time of the image sensor 62 is reduced.
For example, when the found image quality is equal to or greater than a quality threshold, the processor 65 decreases the bit length processed thereby; and when the found image quality is less than the quality threshold, the processor 65 increases the bit length processed thereby. It should be noted that each digital data output from the analog-to-digital converter 64 in the present embodiment has a fixed plurality of bits (for example, N bits). At a relatively short exposure time, the processor 65 processes only the low bit data (lower bit data) of the predetermined bits.
Fig. 7 is a schematic diagram illustrating an operation of a navigation device 600 according to a second embodiment of the present invention, which is operated at a first exposure time or a second exposure time. This embodiment also changes the exposure time of the photodiode in each pixel, for example, in the manner of fig. 2. The image quality can also be calculated in the above manner, and therefore, the description thereof is omitted.
For example, when the image sensor 62 outputs the image frame F at a first exposure time and the found image quality SQCNT is greater than or equal to a first quality threshold TH1, the processor 65 changes the first exposure time to a second exposure time; wherein the second exposure time is less than the first exposure time. In a non-limiting embodiment, when the found image quality SQCNT is greater than or equal to the first quality threshold TH1, the processor 65 processes part of the bits (i.e. less than N bits) of the predetermined bits of each digital data, for example only the lower bits (lower bits data) of the predetermined bits of the digital data and not the other higher bits (high bits data) of the predetermined bits of the digital data; the number of bits of the low-order bit data and the high-order bit data may be determined in advance according to, for example, a desired accuracy, noise immunity, and the like of the processor 65. For example, when the navigation device 600 is operating on a high quality work surface S, the adc 64 outputs 10 bits of digital data, and the processor 65 selects to process 6 bits of low-bit data (shown by the hatched portion in fig. 7), but not other 4 bits of high-bit data (shown by the hatched portion in fig. 7). As the exposure time of the image sensor 62 is reduced, the processor 65 expects that the other high bit data does not have the required working surface S information.
Further, when the image sensor 62 outputs the image frame F at the second exposure time and the found image quality SQCNT is less than or equal to a second quality threshold TH2, the processor 65 changes the second exposure time to the first exposure time; wherein the first quality threshold TH1 may be selected to be equal to or different from the second quality threshold TH 2. In a non-limiting embodiment, the processor 65 processes all bit data (i.e., N bits) of the predetermined bits of each digital data of the digital image when the determined image quality SQCNT is less than or equal to the second quality threshold TH 2.
Thereby, when the navigation device 600 is operated on a high quality (determined according to the comparison of the calculated image quality and the image threshold) working surface S, the processor 65 can process a smaller amount of data during each frame, reducing power consumption.
In the present invention, the above embodiments are described by taking an example in which the analog amplifier is located outside the image sensor, but the present invention is not limited thereto. In other embodiments, a plurality of analog amplifiers are included in the image sensor and respectively correspond to a pixel row or a pixel column, so that the image frame output by the image sensor is the amplified image frame.
It should be noted that, although the above embodiments are described by taking only two conversion resolutions and two exposure times as examples, the invention is not limited thereto. In other embodiments, the analog-to-digital converter may have more than two adjustable resolutions, and the image sensor may have more than two adjustable exposure times. The processor is adapted to process data in a plurality of bit lengths based on a comparison of the image quality to a plurality of quality thresholds. At this point, the processor may adjust the bit length of one step (step) at a time, or adjust multiple steps at a time.
Briefly, the first embodiment of the present invention achieves the object of reducing the amount of data processed by a processor by reducing the analog-to-digital conversion resolution of an analog-to-digital converter; in the second embodiment, the processor controls the image sensor to reduce the exposure time of the image sensor, and simultaneously, the processor actively selects only a part of the fixed bit length of the digital data output by the analog-digital converter to achieve the purpose of reducing the data processing amount of the processor. Furthermore, a shorter exposure time means that the light source (infrared light emitting diode or laser diode) 11 is lit for a shorter time, which means that the energy consumption of the navigation device is further reduced.
It should be understood that the values used in the above embodiments of the present invention, such as the number of pixels, the bit length, and the value of the filter kernel, are only exemplary and not intended to limit the present invention.
In summary, in addition to saving power in the sleep mode or the standby mode, the power consumption of each component in the navigation device needs to be reduced as much as possible. Therefore, the present invention further provides a navigation device (e.g., fig. 1 and 6) and an operating method thereof (e.g., fig. 4-5 and 7), which adjust the amount of data processed by the processor in each frame period (frame period) according to the image quality, so as to achieve the purpose of reducing power consumption.
Although the present invention has been disclosed by way of examples, it is not intended to be limited thereto, and various changes and modifications can be made by one of ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention is subject to the scope defined by the appended claims.

Claims (13)

1. A navigation device, the navigation device comprising:
an image sensor including a pixel array for outputting an image frame;
an analog-to-digital converter for converting each pixel data of the image frame into digital data at a conversion resolution and generating a digital image;
a processor for calculating an image quality of the digital image and decreasing the conversion resolution when the image quality is greater than a quality threshold and increasing the conversion resolution when the image quality is less than the quality threshold; and
an analog amplifier amplifies the each pixel data by a gain value, wherein the processor is further configured to increase the gain value of the analog amplifier and shorten an exposure time of the image sensor when the conversion resolution is decreased.
2. The navigation device of claim 1, wherein
When the analog-to-digital converter generates the digital image at a first resolution and the image quality is greater than a first quality threshold, the processor changes the first resolution to a second resolution, an
When the analog-to-digital converter produces the digital image at the second resolution and the image quality is less than a second quality threshold, the processor changes the second resolution to the first resolution,
wherein the second resolution is less than the first resolution, and the first quality threshold is different from the second quality threshold.
3. The navigation device of claim 1, further comprising a light source for providing light required by the image sensor to acquire the image frames, wherein the processor is further configured to control the light source to shorten a turn-on time per time when the image sensor is controlled to shorten the exposure time.
4. The navigation device of claim 1, wherein the processor synchronously increases the gain value and shortens the exposure time to maintain a maximum grayscale value of the digital image fixed.
5. A navigation device, the navigation device comprising:
an image sensor comprising an array of pixels for outputting an image frame at an exposure time;
an analog-to-digital converter for converting each pixel data of the image frame into digital data of a predetermined bit at a fixed conversion resolution and generating a digital image; and
a processor for calculating an image quality of the digital image and reducing a bit length of the digital data processed thereby and shortening the exposure time of the image sensor when the image quality is greater than a quality threshold, and increasing the bit length of the digital data processed thereby when the image quality is less than the quality threshold.
6. The navigation device of claim 5, wherein
When the image sensor outputs the image frame with a first exposure time and the image quality is greater than a first quality threshold, the processor changes the first exposure time to a second exposure time, and
when the image sensor outputs the image frame at the second exposure time and the image quality is less than a second quality threshold, the processor changes the second exposure time to the first exposure time,
wherein the second exposure time is less than the first exposure time, and the first quality threshold is different from the second quality threshold.
7. The navigation device of claim 5, wherein
When the image quality is greater than a quality threshold, the processor processes a part of bit data in the predetermined bits of the digital data, and
the processor processes all bit data of the predetermined bits of the digital data when the image quality is less than a quality threshold.
8. The navigation device of claim 5, wherein the processor processes lower bit data of the predetermined bits of the digital data and does not process other higher bit data of the predetermined bits of the digital data when the image quality is greater than a quality threshold.
9. A navigation device, the navigation device comprising:
an image sensor comprising an array of pixels for outputting an image frame at an exposure time;
an analog-to-digital converter for converting each pixel data of the image frame into digital data at a conversion resolution and generating a digital image;
a processor for calculating an image quality of the digital image and reducing a bit length of each digital data of the digital image it processes to reduce power consumption when the image quality is greater than a quality threshold; and
an analog amplifier amplifies said each pixel data by a gain value, wherein said processor is further configured to increase said gain value of said analog amplifier and shorten said exposure time while decreasing said bit length of each digital data of said digital image it processes.
10. The navigation device of claim 9, wherein the processor is to reduce the bit length of the each pixel data of the digital image it processes by reducing the conversion resolution of the analog-to-digital converter.
11. The navigation device of claim 9, further comprising a light source for providing light required by the image sensor to acquire the image frames, wherein the processor is further configured to control the light source to shorten a lighting time per one time.
12. The navigation device of claim 9, wherein the processor, in reducing the bit length of the each pixel data of the digital image it processes, is also to reduce the exposure time of the image sensor and fix the conversion resolution of the analog-to-digital converter.
13. The navigation device of claim 12, wherein the each digital data output by the analog-to-digital converter has predetermined bits, the processor processing only low bits of the predetermined bits.
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Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111915654B (en) * 2020-08-10 2024-05-14 无锡英斯特微电子有限公司 Method and system for rapidly exiting sleep state of photoelectric navigation equipment
CN112232278B (en) * 2020-11-04 2024-02-20 上海菲戈恩微电子科技有限公司 3D structured light self-adaptive precision implementation method and system
WO2022146474A1 (en) * 2021-01-04 2022-07-07 Zeku, Inc. Apparatus and method of configurable reduction to signal resolution
US11921940B1 (en) * 2023-03-14 2024-03-05 Pixart Imaging Inc. Optical navigation device capable of automatically switching between different tracking modes in response to different tracking surfaces

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2643394Y (en) * 2003-07-04 2004-09-22 昆盈企业股份有限公司 Illuminance adjustable optical pointer
CN103123536A (en) * 2011-11-21 2013-05-29 原相科技股份有限公司 Displacement detection device and operation method thereof
CN103576911A (en) * 2012-08-08 2014-02-12 原相科技股份有限公司 Displacement detecting device and power saving method thereof
CN103970304A (en) * 2013-02-05 2014-08-06 原相科技股份有限公司 Optical mouse device and method thereof
CN104008522A (en) * 2014-06-13 2014-08-27 无锡英斯特微电子有限公司 Self-adaptation current regulation and control method in photoelectric navigation device

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001285700A (en) * 2000-03-29 2001-10-12 Nec Corp Imaging apparatus
US6891143B2 (en) * 2002-10-30 2005-05-10 Microsoft Corporation Photo-sensor array with pixel-level signal comparison
US20060132443A1 (en) * 2004-12-20 2006-06-22 Chien Wu Francis L Controlling a light source of an optical pointing device based on surface quality
US7399953B2 (en) * 2005-05-06 2008-07-15 Avago Technologies Ecbu Ip Pte Ltd Light source control in optical pointing device
TW200928880A (en) * 2007-12-21 2009-07-01 Pixart Imaging Inc Displacement detection apparatus and method
TWI397003B (en) * 2008-10-23 2013-05-21 Pixart Imaging Inc Image processing method for optical navigator and optical navigator using the same
US9046935B2 (en) * 2008-10-29 2015-06-02 Pixart Imaging Inc. Motion estimation device and power saving method thereof
TWI471521B (en) * 2010-07-23 2015-02-01 Pixart Imaging Inc Displacement estimation method and displacement estimation device using the same
US8780045B2 (en) * 2010-11-19 2014-07-15 Avago Technologies General Ip (Singapore) Pte. Ltd. Optical navigation with a dynamic SQUAL threshold
US9092864B2 (en) * 2010-11-30 2015-07-28 Pixart Imaging Inc Displacement detection apparatus and method
US9269148B2 (en) * 2012-06-11 2016-02-23 Pixart Imaging Inc. Displacement detection device
TWI507929B (en) * 2012-07-27 2015-11-11 Pixart Imaging Inc Displacement detection device and power saving method thereof
TWI499941B (en) * 2013-01-30 2015-09-11 Pixart Imaging Inc Optical mouse apparatus and method used in optical mouse apparatus
TWI471767B (en) * 2013-03-26 2015-02-01 Pixart Imaging Inc Displacement detection device
JP6218635B2 (en) * 2014-02-20 2017-10-25 オリンパス株式会社 Solid-state imaging device and imaging system
US10509493B2 (en) * 2017-06-14 2019-12-17 Pixart Imaging Inc. Navigation device with low power consumption and operating method thereof
US10592007B2 (en) * 2017-07-26 2020-03-17 Logitech Europe S.A. Dual-mode optical input device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2643394Y (en) * 2003-07-04 2004-09-22 昆盈企业股份有限公司 Illuminance adjustable optical pointer
CN103123536A (en) * 2011-11-21 2013-05-29 原相科技股份有限公司 Displacement detection device and operation method thereof
CN103576911A (en) * 2012-08-08 2014-02-12 原相科技股份有限公司 Displacement detecting device and power saving method thereof
CN103970304A (en) * 2013-02-05 2014-08-06 原相科技股份有限公司 Optical mouse device and method thereof
CN104008522A (en) * 2014-06-13 2014-08-27 无锡英斯特微电子有限公司 Self-adaptation current regulation and control method in photoelectric navigation device

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